LOS ANGELES -- A daily glucosamine drink supplement failed to prevent deterioration of knee cartilage, reduce bone bruises or ease knee pain, according to a recent short-term study of the popular, if controversial, dietary product. In a paper published Tuesday in the journal Arthritis & Rheumatology, authors studied the effects of glucosamine hydrochloride on a group of 201 adults for six months. “Our study found no evidence that drinking glucosamine supplement reduced knee cartilage damage, relieved pain or improved function in individuals with chronic knee pain,” said the study’s lead author, Dr. C. Kent Kwoh, professor of medicine and medical imaging at the University of Arizona College of Medicine. “We looked at multiple different ways that glucosamine might help,” said Kwoh, who also directs the University of Arizona Arthritis Center. “None of them showed any benefit.” Glucosamine occurs naturally in humans and other animals, and helps to build cartilage, the tissue that cushions bones.Supplemental glucosamine is commonly made from the shells of sea creatures, and marketers claim that it promotes joint health and supports the formation of cartilage. Roughly 10 percent of the U.S. population uses the supplement, study authors said. In the most recent study, Kwoh and his colleagues tested glucosamine’s effects on adults between 35 and 65 who complained of knee pain. Roughly half of the study patients, 98, were given daily, 1,500 mg doses of glucosamine hydrochloride in a 16-ounce lemonade drink. The other 103 participants were given lemonade drinks that did not contain the supplement.The study subjects were given MRIs at the start of the trial and at the final 24-week examination. Test subjects also reported on their knee pain.

Study authors said theirs was the first to use MRIs to evaluate glucosamine’s effects on cartilage and bone marrow lesions.Previous studies have used X-rays, which show bones, but not cartilage. Doctors therefore judge how healthy the invisible cartilage is by measuring how far apart the bones of the knee are. Larger distances suggest more cartilage.With MRI technology, Kwoh said he and his colleagues were able to examine the cartilage more directly.